Home Grown is an educational,
entertaining, question-answer column seen weekly in "News from
the Genesee MSUE Office," a weekly newsletter for Genesee
County Master Gardeners. Special thanks to the Genesee, Oakland and
Livingston county MSU Extension offices for providing this service.

HOME GROWN 311

I have a large maple that is right next to the road. Many of the leaves, especially on the road side, have brown edges around them. What kind of insect or disease is causing this?

All the insects and diseases are free to leave, with no charges filed. Your problem has do with a common maple problem called leaf scorch. For any one or multiple reasons, moisture isn’t being picked up in enough quantity to replace moisture being lost by the leaves. Here are just some of your choices. There may insufficient ground moisture because it hasn’t rained enough. It could be caused by excessive heat and we’ve certainly had that. The road could be reflecting back more heat and drying the roadside leaves. The soil will certainly be compacted under the road, causing less root growth. The tree’s roots could be growing in clay, which can slow root growth and there just aren’t enough roots to do the job during the hot weather. There may be a salt residual in the soil from winter road salting. When conditions get hot and or dry, this may be the factor causing the leaf scorch. It could be a manganese deficiency in the soil. This all adds up to a huge number of “coulds.” Start by checking the moisture in the root area. This tree’s roots could extend twice as far as the branches, so this
makes a big area. Try watering if the soil is dry. There are some issues that you will not have any control over and you may have to live with what you cannot fix.

I am growing several rows of green beans in my garden for the first time. How do I know when it is time to pick them? Also, I am worried about my bush zucchini plants. There are gray or silver marks on the leaves. I think this is fungus but the leaves look green and the plants
are growing like crazy. I hope these plants are going to make it.

The plants will make it but how about you? When picking green beans, look at the size of the beans. They should be several inches long and smooth. Don’t wait until the beans look like a snake that has swallowed several golf balls. Green beans should be tender and moist. You should be able to steam or cook them for a short period of time before eating. If you wait until they are lumpy, they become leathery. But some people like them like that. They cook them half a day with a chunk of bacon or fatback. Go out and pick every day because you want to get the beans at
the peak of perfection. They won’t hang around on the plants like that for long. I hope you are planning on freezing these or have a big family. Several rows mean many beans appearing daily. For the zucchini plants, most bush zucchinis have silvery markings that appear as the leaves
begin to enlarge. It’s a normal part of that plant. If you had a fungal problem, the leaves would possibly be yellowed. There might be dark rounded spots. If there were a mildew problem, it would look powdery or dusty. Leaves would be turning
an unhealthy yellow color.